Not so much hunting, taka kaira has them listed on the site and comes with the correct throwout bearing. I believe it was 2-2500 for the quad-plate. pretty reasonable to me. Is the carbon carbon you refer to from rps ? Both great and sad stories from that company, but regardless, more options for the r154.
Im not here to argue but there are a lot of people running the stock 6spd w/ power. Ryan Woon from WOTM is almost making 1300rwhp on the 6 spd and trapping 171, Gary White who's trapping 180 in the 1/4 is also on the stock 6spd. Boost Logic, i believe their other car, traps 172 w/ the stock 6spd, Dana Dichara with a 171 on the 6spd. Few of these cars make this trap speed are also full weight as well, thats 3500+. we can go all day listing the fast 6spd's. The people running the th400, power glide, l40e, etc just want to run, and time more reliably/consistently in the 1/4. I say you can go wrong both ways, but some people regret going auto. the high rpm's @ highway speeds, no more "fun" driving around town, etc... but that is all subjective.